package removecomom;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Scanner;

public class Main {//字符串·去重
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();
        scanner.close();
        HashSet<Character> hs = new HashSet<>();
        for (int i = 0; i < str.length(); i++) {
            char ch=str.charAt(i);
            hs.add(ch);
        }
        Iterator<Character> ch= hs.iterator();
        while (ch.hasNext()){
            System.out.print(ch.next());
        }
    }
}
